Buggy code:
} else { this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 1 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; } } else { this . printErrorAndExit ( ( ( ( ( "ADD<seq2seq4repair_space>takes<seq2seq4repair_space>exactly<seq2seq4repair_space>" + arguments ) + "<seq2seq4repair_space>arguments<seq2seq4repair_space>(" ) + ( ( segments . size ( ) ) - 1 ) ) + "<seq2seq4repair_space>given)" ) ) ; } } else if ( segments . get ( 0 ) . equals ( "ASSIGN" ) ) { arguments = 2 ; if ( ( segments . size ( ) ) == ( arguments + 1 ) ) { if ( variables . containsKey ( segments . get ( 1 ) ) ) { variables . put ( segments . get ( 1 ) , Double . parseDouble ( segments . get ( 2 ) ) ) ; this . printOutput ( ( ( ( "ASSIGN<seq2seq4repair_space>" + ( segments . get ( 2 ) ) ) + "<seq2seq4repair_space>to<seq2seq4repair_space>" ) + ( segments . get ( 1 ) ) ) ) ; } else { this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 1 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; } } else { this . printErrorAndExit ( ( ( ( ( "ASSIGN<seq2seq4repair_space>takes<seq2seq4repair_space>exactly<seq2seq4repair_space>" + arguments ) + "<seq2seq4repair_space>arguments<seq2seq4repair_space>(" ) + ( ( segments . size ( ) ) - 1 ) ) + "<seq2seq4repair_space>given)" ) ) ; } } else if ( segments . get ( 0 ) . equals ( "CMT" ) ) { } else if ( segments . get ( 0 ) . equals ( "DIV" ) ) { arguments = 3 ; if ( ( segments . size ( ) ) == ( arguments + 1 ) ) { if ( variables . containsKey ( segments . get ( 1 ) ) ) { if ( variables . containsKey ( segments . get ( 2 ) ) ) { if ( variables . containsKey ( segments . get ( 3 ) ) ) { variables . put ( segments . get ( 3 ) , ( ( variables . get ( segments . get ( 1 ) ) ) // ( variables . get ( segments . get ( 2 ) ) ) ) ) ; this . printOutput ( ( ( ( ( ( "DIV<seq2seq4repair_space>" + ( segments . get ( 1 ) ) ) + "<seq2seq4repair_space>by<seq2seq4repair_space>" ) + ( segments . get ( 2 ) ) ) + "<seq2seq4repair_space>and<seq2seq4repair_space>set<seq2seq4repair_space>to<seq2seq4repair_space>" ) + ( segments . get ( 3 ) ) ) ) ; } else { this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 3 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; } } else { this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 2 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; } } else { this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 1 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; } } else { this . printErrorAndExit ( ( ( ( ( "DIV<seq2seq4repair_space>takes<seq2seq4repair_space>exactly<seq2seq4repair_space>" + arguments ) + "<seq2seq4repair_space>arguments<seq2seq4repair_space>(" ) + ( ( segments . size ( ) ) - 1 ) ) + "<seq2seq4repair_space>given)" ) ) ; } } else if ( segments . get ( 0 ) . equals ( "END" ) ) { } else if ( segments . get ( 0 ) . equals ( "ENTER" ) ) { arguments = 1 ; if ( ( segments . size ( ) ) == ( arguments + 1 ) ) { if ( variables . containsKey ( segments . get ( 1 ) ) ) { Scanner scanner = new Scanner ( System . in ) ; variables . put ( segments . get ( 1 ) , scanner . nextDouble ( ) ) ; } else { <START_BUG> this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 2 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; <END_BUG> } } else { this . printErrorAndExit ( ( ( ( ( "ENTER<seq2seq4repair_space>takes<seq2seq4repair_space>exactly<seq2seq4repair_space>" + arguments ) + "<seq2seq4repair_space>arguments<seq2seq4repair_space>(" ) + ( ( segments . size ( ) ) - 1 ) ) + "<seq2seq4repair_space>given)" ) ) ; } } else if ( segments . get ( 0 ) . equals ( "INC" ) ) { } else if ( segments . get ( 0 ) . equals ( "MUL" ) ) { } else if ( segments . get ( 0 ) . equals ( "PRINT" ) ) { arguments = 1 ; if ( ( segments . size ( ) ) == ( arguments + 1 ) ) { if ( variables . containsKey ( segments . get ( 1 ) ) ) { this . printOutput ( Double . toString ( variables . get ( segments . get ( 1 ) ) ) ) ; } else { this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 1 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ; } } else { this . printErrorAndExit ( ( ( ( ( "PRINT<seq2seq4repair_space>takes<seq2seq4repair_space>exactly<seq2seq4repair_space>" + arguments ) + "<seq2seq4repair_space>argument<seq2seq4repair_space>(" ) + ( ( segments . size ( ) ) - 1 ) ) + "<seq2seq4repair_space>given)" ) ) ; } } else if ( segments . get ( 0 ) . equals ( "START" ) ) { } else if ( segments . get ( 0 ) . equals ( "SUB" ) ) { } else if ( segments . get ( 0 ) . equals ( "VAR" ) ) { arguments = 1 ;

Fix:
this . printErrorAndExit ( ( ( "name<seq2seq4repair_space>" + ( segments . get ( 1 ) ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>defined" ) ) ;